Gust of Hot Air is a blog outlining my own statistical analysis of Australian Weather. I am Jonathan Lowe, and have completed by Bsc(hons) in statistical analysis as well as my Master of Science. I have done 2 years of my PhD
There is a lot of statistical information regarding climate change and I intend to provide statistical analysis into the area to prove if the recent well advertised rise in temperature is at all statistically significant. Results will be uploaded here on a regular basis

Thursday, December 17, 2009

One would expect that a greater amount of cloud cover would result in a lower temperature and a lower amount of cloud cover would result in a greater temperature. We should previously that the amount of cloud cover in Australia has been decreasing since 1950, and we also showed that temperatures in Australia have been increasing, especially during the middle of the day, and temperatures have not been increasing during the night.

So what influence does the amount of cloud cover have on Australian temperatures during certain parts of the day and night? Shown below are the graphs of cloud cover anomalies verses temperature anomalies since 1950.

So what is quite clear from the above graphs is the clear relationship between cloud cover and temperature during the day. All relationships were significant apart from 9pm and Midnight, where no significant relationship was found. Interestingly, the relationship between cloud cover and temperature at 3am and 6am was positive, in that greater amounts of cloud cover was related to greater temperatures.

This is not that surprising, as cloud cover at night works as a blanket, helping to keep the temperature in. From 9am until 6pm, the relationship is undeniably negative, in that lower amounts of cloud cover is related to higher temperatures, and greater amounts of cloud cover is related to lower temperatures.

This is summarised in the graph below:

Here we can see that the strength of the relationship increases until Noon/3pm and decreases after/before this.

So it is clear that cloud cover amounts have a very strong relationship with temperature, as we previous hypothesised. As we showed previously that cloud cover levels in Australia, especially during the day, have been decreasing, what effect does this have on temperature?

Can we adjust the temperatures for this decrease in cloud cover? What effect will that have on the long term averages on Australian temperature? We will find this out in the next post.